Germany's MediGene has called a halt to a Phase I study of its experimental rheumatoid arthritis drug RhuDex after one of the 12 participants on the trial died.

The Martinsried-based company noted that the volunteer, a 48-year-old man from Edinburgh, suffered a heart problem "some days after one of the scheduled treatments" of RhuDex, an orally-available CD80 inhibitor. The patient was subsequently treated in hospital and discharged a few days later but several days on, he died at home. MediGene said that investigations into the cause of death will be carried out "but it is currently unclear whether or not there is any correlation between this sad event and the drug administration".

The firm, which reported the event immediately to the relevant authorities, said that so far, about 80 individuals have been treated with RhuDex "and no comparable events occurred in the other subjects in this study or in previous clinical studies". The eleven other volunteers included in the current Phase I study showed only mild side effects like headaches but for the timebeing, the latter has been put on hold.